Overhead frame structures are typically fabricated of one or more members forming a framework. Such structures can be used on a vehicle for one or more reasons. The structures can be utilized to protect an operator from injury in the event of accidental upset or inadvertent rollover of the vehicle. Additionally, the structures can be used for mounting various accessories thereto. Further, the frameworks of the structures can be used to mount enclosure elements thereto.
While mounting an overhead frame structure on a vehicle may be advantageous for a variety of reasons as exemplified above, certain situations may exist in which one would want to temporarily modify the structure's configuration. For example, in many cases, as a result of the structure being mounted to the vehicle, the vehicle's height is increased significantly. Consequently, the process of maneuvering the vehicle in low overhead clearance areas may be difficult or not feasible. To address such scenarios, certain overhead frame structures have been designed to be adjustable. For example, in some designs, an upper section of the structure is made adjustable with respect to a lower section of the structure. Accordingly, the upper section can be lowered with respect to the lower section to temporarily reduce the overall height of the overhead frame structure. In some designs, this adjustment is facilitated by removal of at least one arresting device used to hold the upper section in its position, either directly or through the use of an interconnecting bracket. In such designs, the arresting members can involve fasteners such as linchpins, which enable quick changeover of the overhead frame structure from one configuration (e.g., with upper section being raised) to another configuration (e.g., with upper section being lowered).
However, while the adjustability of these overhead frame structures can be viewed as advantageous, upon being adjusted to their lowered configuration, the structures fall short of meeting industry-recognized standards for rollover protection. Particularly, when the upper sections of such structures are lowered, their corresponding crossbars are positioned at a height not meeting the standard requirements for providing rollover protection for the operator. Further, after the structure is adjusted to its lowered configuration, the operator may continue to leave the upper section lowered for extended periods of time. Consequently, during these periods of time, the structures continue to fall short of meeting industry-recognized standards for rollover protection.
Embodiments of the present invention are directed to addressing these limitations.